Lighters such as those used for igniting tobacco products, such as cigars, cigarettes, and pipes, have developed over a number of years. Typically, these lighters use either a rotary friction element or a piezoelectric element to generate a spark in proximity to a nozzle emitting fuel from a fuel container. Piezoelectric mechanisms have gained universal acceptance because they are simple to use. One such piezoelectric mechanism is disclosed in U.S. Pat. No. 5,262,697 ("the '697 patent"). The disclosure of the '697 patent is incorporated by reference herein.
Lighters have also evolved from the small, hand-held lighters to several forms of extended lighters. These lighters are also hand held, but are more useful for general purposes such as lighting candles, barbecue grills, fireplaces and campfires. Earlier attempts at such designs relied simply on extended actuating handles to house a typical lighter at the end. Examples of this concept are found in U.S. Pat. Nos. 4,259,059 and 4,462,791.
In addition, many general purpose lighters have had some form of operating mechanism for resisting undesired operation of the lighter by young children. Often, these mechanisms take the form of on/off switches that may shut off the fuel source or may completely prevent movement of an actuator, such as a push-button, on the lighter. While it is desirable to inhibit certain operation of lighters, such as use by children, it is also desirable to maintain good function.
Moreover, the use of on/off switches that must be positively moved by the user between "on" and "off" positions has drawbacks. For example, an adult user may forget to move the switch back to the "off" position after use and thereby render the feature ineffective.
Further problems are specific to lighters incorporating piezoelectric mechanisms. In particular, to use these mechanisms in extended length lighter devices, wires have normally been required to connect the piezoelectric mechanism to the forward end of the lighter proximate the fuel nozzle. One prior concept that eliminates the wires typically associated with a piezoelectric mechanism is U.S. Pat. No. 5,154,601. This lighter places the piezoelectric element proximate the forward end of the lighter with one end of the piezoelectric element in direct contact with the burner or nozzle, while the opposite end is in contact with a tube forming part of a push button assembly. The push button assembly is electrically conductive and, during actuation, slides against a metal housing portion. While this construction does eliminate the use of wires, the design also requires contact between a moving push button and a housing portion to complete the electrical circuit. This contact not only relies on close tolerances during manufacture but, over time, the push button may lose electrical contact with the metal housing portion. This is especially true if wear creates a gap between the push button and the metal housing portion. Moreover, the design requires that the user move the push button in a forward direction rather than a more ergonomic and easily accomplished rearward direction of a trigger or inward direction of a push button.
Controlling the electrically generated spark is another problem which is specific to piezoelectric mechanisms. In order to ignite the fuel exiting from the nozzle, it is necessary that the spark be created in the vicinity of the fuel. It is, therefore, desirable to provide a utility lighter which reliably produces a spark at a precise location near the nozzle in order to effectively ignite the fuel exiting from the nozzle.
Another factor requiring consideration in the design of utility lighters is the spacing between the fuel supply and the exit nozzle. Since fuel containers are typically located in the handle of the lighter and the nozzle is located at the end of a wand, the fuel from the fuel container is required to reach the nozzle via a conduit. Once the fuel is released from the fuel container by depressing an actuator and opening a valve, the fuel travels down the fuel conduit and ultimately exits through the nozzle. It is desirable to time the arrival of the spark such that fuel is present at the nozzle exit when the spark is created in order to consistently and reliably ignite the lighter. In addition, manufacturing tolerances play a role in when the fuel reaches the nozzle and when the spark is generated. Thus, it is also desirable to minimize the effects of manufacturing tolerances.
Thus, there remains a need for a utility lighter which resists unwanted actuation, minimizes wiring, ignites efficiently and reliably, and minimizes the impact of manufacturing variances.